New research in LCNTDR's collection in Parasites and Vectors

A new series of research articles have been added to LCNTDR's research collection,  'Advances in Scientific Research for NTD Control' in the journal, Parasites & Vectors. 

This special series features recent advances in scientific research for NTD control executed by LCNTDR member institutions and their collaborators.  It reflects the diversity of LCNTDR member expertise in terms of disease type, academic discipline and geographical location.

It further highlights the work being undertaken by the LCNTDR towards achieving the United Nations Sustainable Development Goals as well as supporting the objectives of the London Declaration on Neglected Tropical Diseases.

• Conjunctival transcriptome profiling of Solomon Islanders with active trachoma in the absence of Chlamydia trachomatis infection. Parasites & Vectors 2018 11:104
  Hristina Vasileva, Robert Butcher, Harry Pickering, Oliver Sokana, Kelvin Jack, Anthony W. Solomon, Martin J. Holland and Chrissy h. Roberts
  Clinical signs of active (inflammatory) trachoma are found in many children in the Solomon Islands, but blood tests of these individuals showed that majority had no evidence of previous infection with Chlamydia trachomatis. This paper investigates whether host responses in these children were the same or different to those typical of trachoma caused by Chlamydia. The findings show that the gene expression of children on Solomon Islands with clinical signs but no infection do not follow the typical tissue gene expression of trachoma children found in endemic communities in Africa. This raises further questions about the use of clinical signs alone in the treatment of trachoma. 

   

• Evaluation of a Chlamydia trachomatis-specific, commercial, real-time PCR for use with ocular swabs: lay summary. Parasites & Vectors 2018 11:102
  Harry Pickering, Martin J. Holland, Anna R. Last, Matthew J. Burton and Sarah E. Burr.
  Trachoma infections are confirmed by testing for the presence of C. trachomatis DNA. This study evaluated the performance of a commercial test (Fast-Track) against a previously validated commercial test and a test developed in-house, for use with ocular samples. The Fast-Track test performed similarly to the comparators, but incorrectly identified some samples as containing C. trachomatis DNA. This study also developed a novel, bias-free approach for converting the results of these tests into a simple yes-no answer for the presence of C. trachomatis DNA. 

   

• Histopathological and immunohistochemical characterisation of hepatic granulomas in Leishmania donovani-infected BALB/c mice: a time-course study. Parasites & Vectors 2018 11:73
  Francisco J. Salguero, Waldo L. Garcia-Jimenez, Isadora Lima, Karin Seifert.
  At present, there is no effective vaccine for symptomatic Visceral leishmaniasis and available chemotherapies have limitations. Understanding the local immune mechanisms required for the control of infection is a key factor for developing effective vaccines and therapeutics. This study investigated the development of the typical granulomatous lesions in the liver in experimental VL over time, together with the local immune responses. Using histopathology and immunohistochemical techniques this study highlighted the role of macrophages during the early stage of infection and the establishment of a lymphocytic response to control the infection in more advanced stages. 

   

• Identifying co-endemic areas for major filarial infections in sub-Saharan Africa: seeking synergies and preventing severe adverse events during mass drug administration campaigns. Parasites & Vectors 2018 11:70
  Jorge Cano, Maria-Gloria Basáñez, Simon J. O’Hanlon, Afework H. Tekle, Samuel Wanji, Honorat G. Zouré, Maria P. Rebollo and Rachel L. Pullan.
  Current control strategies for onchocerciasis and lymphatic filariasis (LF) are built upon community-directed mass drug administration. When distributing microfilaricides considerable care is needed to minimise the risk of severe adverse events (SAEs) in areas that are co-endemic for onchocerciasis or LF and loiasis. This work combines previously published predictive risk maps for onchocerciasis, LF and loiasis to (i) explore the scale of spatial heterogeneity in co-distributions, (ii) delineate target populations for different treatment strategies, and (iii) quantify populations at risk of SAEs across the continent. 

   

• Helminth lifespan interacts with non-compliance in reducing the effectiveness of anthelmintic treatment. Parasites & Vectors 2018 11:66
  Sam H. Farrell and  Roy M. Anderson.
  The success of mass treatment programmes targeting the soil-transmitted helminths depends on regular take-up of annual or biannual treatment. Individuals who are systematically untreated may contribute disproportionately to the pool of infection in a community. This article investigates the impact of the lifespan of the parasite on this effect using a computational model of parasite transmission, and finds that treatment of longer-lived parasites in particular would benefit from efforts to increase regular treatment uptake. It discusses the urgent need for more detailed data collection for the benefit of future studies in this area. 

   

• Current epidemiological evidence for predisposition to high or low intensity human helminth infection. Parasites & Vectors 2018 11:65
  James E. Wright, Marleen Werkman, Julia C. Dunn & Roy M. Anderson.
  As the incidences of helminth infections decreases in targeting communities, elimination strategies which focus on treating entire populations may no longer be the most efficient or cost-effective. It may be more beneficial to identify those who are persistently infected, often termed as being “predisposed” to infection, and target treatment at them. This systematic review sought to collate all current evidence regarding predisposition to helminth infection. Whilst consistent evidence of predisposition to heavy (and light) infection for certain human helminth species was found, further research is needed to identify underlying reasons for the reported differences between demographic groups. 

   

• The impact of a single round of community mass treatment with azithromycin on disease severity and ocular Chlamydia trachomatis load in treatment-naïve trachoma-endemic island communities in West Africa. Parasites & Vectors 2017 10:624
  Anna R. Last, Sarah E. Burr, Emma Harding-Esch, Eunice Cassama, Meno Nabicassa, Chrissy h. Roberts, David C. W. Mabey, Martin J. Holland and Robin L. Bailey.
  To reduce the transmission of trachoma in endemic communities the World Health Organization recommends three annual rounds of mass drug administration (MDA) for all members of the community with the antibiotic azithromycin. This study evaluates the impact of a single round of MDA in treatment-naïve trachoma-endemic island communities on the Bijagos Archipelago of Guinea-Bissau. Using novel Ct diagnostic tests and geospatial mapping techniques, the findings show significant reduction in Ct infection and severity of infection, suggesting the beginning of trachoma control in these communities. These findings will helps us to understand the impact of MDA and determine when trachoma has been eliminated. 

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